Diamonds are the premium ingame currency in the game. With Diamonds, you can buy equipment or misc. stuff in the Mystery shop, Cashapon (Luck based) and Diamonds-Store.
By buying Diamonds, you can upgrade your VIP Level. The first 3 VIP Levels can be gained for free, but the rest must be gained by buying diamonds. The different VIP Levels give different bonuses.
Purchase Bonus Edit
If you buy Diamonds, you can get the daily Purchase Bonus, and the purchase bonus based on how many diamonds you already purchased. You can get different items, for example after purchasing 2580 Diamonds you can claim a reward for precious pet eggs and more. The General purchase bonus can be found in the VIP-Window.
If you have diamonds, you can buy alot of useful stuff in the diamond store. For example a Skin which gives bonuses, Soul Stones, unseal runes and more.
Mysterious Shop Edit
In the Mysterious shop, you can find a Gold-Part and a Diamond-Part. In the diamond part, there are usually more useful stuff, but it only resets once a day. Sometimes, you can find Super- Pet Eggs in the diamond part. (Which cost 1680 diamonds.) Only use diamonds for the Mysterious Shop if there is really something awesome..!
Upgrading (-Additions) Edit
With Diamonds, you can get additional daily upgrade counts for stuff like pet feeding, off hand upgrading etc.! With these, you can buy new upgrades! Also, there can be bought upgrades in general with diamonds. They give more Upgrading EXP at pet feeding for example. Also, it can be used to increase success rates at enhancing and forging.
In the Cashapon, you can buy tickets to get rare items. I know a user that has won one of these rare items, but used 12k Diamonds, so I would appreciate to do it. But its your choice!
In your or the Guild of others, you can use Diamonds for the daily wish, second training (50 diamonds), feeding the guild pet and buying new guild pets. There are only two guilds at this server (of which one is down), the one online is "Zhiars Mastery", which have the new guild pets. With them, you can claim super overpowered rewards. The medium pet costs 50.000 diamonds, the Superior 100.000 diamonds.
How to get Diamonds Edit
Purchasing them Edit
The easiest method is purchasing. You pay your real money and get these Diamonds. Not much to say about it. One thing to keep in mind is, that if the server will reset, you get more diamonds at the new servers from the gameguyz support, but will not get your VIP-Level back.
Getting them for Free Edit
The other(/harder?) way to get diamonds is, which only works on kongregate, to complete third-party offers to get free kreds (TrialPay). With these, you can buy diamonds for free!